Benchmarking adjustment

- Fix iteration limit check in main BatchPDLP loop to occur before checking for optimality/(in)feasibility. Now, if an LP finishes exactly at the iteration limit, it will be counted as a finished solve rather than as hitting the iteration limit.
- Add clarity/consistency to benchmark example list.
- Clean up benchmarking file and save all results to CSVs, rather than only storing summary results.

Author: RXGottlieb